A novel nomogram provides improved accuracy for predicting biochemical recurrence after radical prostatectomy

Area of Science:

• Urology
• Oncology
• Medical Imaging

Background:

• Existing prediction tools for biochemical recurrence (BCR) after radical prostatectomy (RP) often do not simultaneously utilize serum prostate-specific antigen (PSA) nadir and maximum tumor diameter (MTD).
• There is a need for improved prediction models for BCR-free survival (BCRFS) post-RP.

Purpose of the Study:

• To develop and validate a novel nomogram for predicting BCRFS after RP.
• To incorporate MTD and PSA nadir as key predictors in the nomogram.
• To compare the predictive performance of the new nomogram against existing scores like CAPRA-S.

Main Methods:

• Retrospective analysis of 337 patients who underwent RP.
• Measurement of MTD from pre-operative MRI scans.
• Development of a nomogram using Cox regression, incorporating PSA nadir, MTD, Gleason score, surgical margin (SM), and seminal vesicle invasion (SVI).
• Validation using time-dependent ROC and decision curve analyses.

Main Results:

• A novel nomogram was developed, incorporating PSA nadir, MTD, Gleason score, SM, and SVI, all significant predictors of BCR (P < 0.05).
• The new nomogram demonstrated a higher concordance index (0.76) compared to the CAPRA-S score (0.70) and a basic model (0.66).
• Time-dependent ROC and decision curve analyses confirmed the superior predictive advantage of the new nomogram.

Conclusions:

• Serum PSA nadir post-RP and MTD from pre-operative MRI are independent predictors of BCR.
• The newly developed nomogram, integrating PSA nadir and MTD, significantly enhances the accuracy of predicting BCRFS after RP.
• This tool offers improved risk stratification for patients undergoing RP.